Contents
Key Stage 1
Meaning
A leaf is part of a plant that is joined to the stem above the ground.
About Leaves
Leaves are usually green and shaped like a blade or a needle. Some plants have red leaves and in some plants the leaves fall off in autumn.
Examples
These are the leaves on a Horse Chestnut Tree. | This is a leaf from a Beech Tree | This is an Oak Tree leaf. |
3 leaves from an Ash Tree. | A Silver Birch Tree leaf. | These are the leaves of a Cedar Tree |
These are the leaves of a Fir Tree. | These Pine Tree leaves are called Pine Needles. | These are the leaves of a Holly Tree. |
Key Stage 2
Key Stage 3
Meaning
A leaf is an organ in the shoot system of a plant that uses photosynthesis to produce food for the plant.
About Leaves
- The cells in leaves have many chloroplasts inside them.
- Leaves produce food that is sent to the roots through the phloem which is part of a Plant Vein that carries sap.
Leaves have many tissues inside them found in layers:
- Upper Epidermis - A layer of cells at the top of the leaf that make a waxy cuticle on top to keep the leaf waterproof.
- Palisade Tissue - A layer of palisade cells which have lots of chloroplasts in them for photosynthesis.
- Spongy Mesophyll Tissue - A layer of spongy mesophyll cells that have irregular shapes to allow air to pass through the leaf.
- Lower Epidermis - A layer of cells at the bottom of the leaf with stomata to allow air into and out of the leaf.
A diagram of the cross section of a leaf showing Palisade Cells, Spongy Mesophyll Cells and Guard Cells. |